Video encoding apparatus and method

ABSTRACT

A video encoding apparatus includes a motion estimation module, an information providing module, a filtering module, a motion compensation module, and a converting module. The motion estimation module performs a plurality of modes of motion estimations on macro-blocks included in an input frame and provides a motion-estimated frame which conforms to a predetermined standard. The information providing module receives motion vectors and mode information of the plurality of modes of motion estimations to provide an encoding information signal. The filtering module filters the motion-estimated frame to provide a filtered frame based on the encoding information signal. The motion compensation module performs motion compensation on the filtered frame to provide a motion-compensated frame. The converting module performs a spatial conversion on the motion-compensated frame.

BACKGROUND

1. Field

Example embodiments relate to encoding and, more particularly, to videoencoding apparatus and a video encoding method.

2. Description of the Related Art

As information communication over the interne increases, videocommunication, in addition to voice communication, increases. To satisfyincreasing demands of consumers for text, images, music, and so forth,demands on multimedia services increases. Multimedia includes hugeamount of data, requiring a large capacity storage media. In addition,transmission of multimedia data requires wide bandwidth. Therefore,compressive encoding is essential for transmitting multimedia data.

SUMMARY

Embodiments are therefore directed to a video encoding apparatus andmethod, which substantially overcomes one or more of the problems due tothe limitations and disadvantages of the related art.

It is therefore a feature of an embodiment to provide a video encodingapparatus and method having enhanced performance using additionalencoding information.

It is yet another feature of an embodiment to provide video encodingapparatus and method that prevent bit rates from increasing by includinga filter inside the video encoding apparatus and using additionalencoding information.

It is still therefore a feature of an embodiment to provide videoencoding apparatus and method that prevent image quality from beingdegraded by including a filter inside the video encoding apparatus andusing additional encoding information.

At least one of the above and other features and advantages may berealized by providing a video encoding apparatus including a motionestimation module, an information providing module, a filtering module,a motion compensation module, and a converting module. The motionestimation module performs a plurality of modes of motion estimations onmacro-blocks included in an input frame and provides a motion-estimatedframe which conforms to a predetermined standard. The informationproviding module receives motion vectors and mode information of theplurality of modes of motion estimations to provide an encodinginformation signal. The filtering module filters the motion-estimatedframe to provide a filtered frame based on the encoding informationsignal. The motion compensation module performs motion compensation onthe filtered frame to provide a motion-compensated frame. The convertingmodule performs spatial conversion on the motion-compensated frame.

The predetermined standard may be associated with each cost of theplurality of modes of motion estimations preformed on the macro-blocks.

The cost of the mode of motion estimation conforming to thepredetermined standard may be lower than costs of other modes of motionestimations.

The plurality of modes of motion estimations may be performed byreferring to a reference frame.

The motion estimation module may include a motion estimation unit thatperforms the plurality of modes of motion estimations on each of themacro-blocks by referring corresponding blocks of the reference frame togenerate corresponding motion vectors and a mode decision unit thatdecides which one of the modes conforms to the predetermined standard.

The encoding information signal may include at least the motion vectors,the mode information, a partition type of the macro-blocks, a type ofthe macro-blocks, and a quantization parameter of the macro-blocks.

The filtering module may include a two dimensional filter that filtersthe motion-estimated frame in two dimensions, a multiplexer that selectsone of the motion-estimated frame and an output of the two dimensionalfilter in response to the encoding information signal, a switch thatselectively provides the reference frame according to the encodinginformation signal, and a coupler that selectively couples the output ofthe multiplexer and the reference frame which is selectively provided,to provide the filtered frame according to the encoding informationsignal.

The multiplexer may select the output of the two dimensional filter, theswitch is opened and the coupler provides output of the two dimensionalfilter when the encoding information signal indicates an intra-mode.

When the encoding information signal indicates an inter-mode, themultiplexer may select the motion-estimated frame, the switch may beclosed, and the coupler may provide a frame in which themotion-estimated frame is coupled with the reference frame as thefiltered frame

The motion estimation module and the filtering module may operate as athird-dimensional noise canceller when the motion estimation module andthe filtering module are coupled to each other.

The filtering module may include a two dimensional filter that filtersthe motion-estimated frame in two dimensions, a multiplexer that selectsone of the motion-estimated frame and an output of the two dimensionalfilter in response to the encoding information signal, a buffer thatstores the reference frame to selectively provide the stored referenceframe according to the encoding information signal, and a coupler thatselectively couples the output of the multiplexer and the referenceframe which is selectively provided, to provide the filtered frameaccording to the encoding information signal.

The converting module may include a discrete cosine transformation (DCT)unit that performs DCT on the motion-estimated frame to generate a DCTcoefficient and a quantization unit that performs quantization on theDCT coefficient to generate a quantization coefficient.

The video encoding apparatus may further include a recovery module thatrecovers the spatial-converted frame to provide a recovered frame and astorage unit that stores the recovered frame to provide the storedrecovered frame as the reference frame.

The recovery module may include an inverse quantization unit thatperforms the inverse quantization on the spatial converted frame and aninverse discrete cosine transformation that performs the inversediscrete cosine transformation on the inversely quantized frame toprovide the recovered frame.

According to example embodiments, in a video encoding method, aplurality of modes of motion estimations is performed on macro-blocksincluded in an input frame by referring to a reference frame to providea motion-estimated frame which conforms to a predetermined standard. Themotion-estimated frame is filtered to provide a filtered frame accordingto an encoding information signal including motion vectors of theplurality of modes of motion estimations and mode information of theplurality of modes of motion estimations. Motion compensation isperformed on the filtered frame. Spatial conversion is performed on themotion-compensated frame.

The predetermined standard may be associated with each cost of theplurality of modes of motion estimations preformed on the macro-blocks.

The spatial conversion may be performed on the motion-compensated framefor canceling spatial overlap in the motion-compensated frame.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages will become more apparent tothose of ordinary skill in the art by describing in detail exemplaryembodiments with reference to the attached drawings, in which:

FIG. 1 illustrates a block diagram of a video encoding apparatusaccording to some example embodiments.

FIG. 2 illustrates a block diagram of an example of the motionestimation module in FIG. 1 according to some example embodiments.

FIG. 3 illustrates an example of the filtering module in FIG. 1according to some example embodiments.

FIG. 4 illustrates a block diagram of an example of the convertingmodule in FIG. 1 according to some example embodiments.

FIG. 5 illustrates a block diagram of an example of a recovery module inFIG. 1 according to some example embodiments.

FIG. 6 illustrates a block diagram of a video encoding apparatusaccording to other example embodiments.

FIG. 7 illustrates an example of the filtering module in FIG. 6according to some example embodiments.

FIGS. 8A and 8B illustrate simulation diagrams of peak signal to noiseratio of the video encoding apparatus according to some exampleembodiments.

FIGS. 9A and 9B illustrate simulation diagrams of structural similarityindex measurement of the video encoding apparatus according to someexample embodiments.

FIG. 10 illustrates a flow chart of a video encoding method according tosome example embodiments.

DETAILED DESCRIPTION

Korean Patent Application No. 10-2009-0103890, filed on Oct. 30, 2009,in the Korean Intellectual Property Office, and entitled: “VideoEncoding Apparatus and Method,” is incorporated by reference herein inits entirety.

Various example embodiments will be described more fully hereinafterwith reference to the accompanying drawings, in which some exampleembodiments are shown. The present inventive concept may, however, beembodied in many different forms and should not be construed as limitedto the example embodiments set forth herein. Rather, these exampleembodiments are provided so that this disclosure will be thorough andcomplete, and will fully convey the scope of the present inventiveconcept to those skilled in the art. In the drawings, the sizes andrelative sizes of layers and regions may be exaggerated for clarity.Like numerals refer to like elements throughout.

It will be understood that, although the terms first, second, third,etc. may be used herein to describe various elements, these elementsshould not be limited by these terms. These terms are used todistinguish one element from another. Thus, a first element discussedbelow could be termed a second element without departing from theteachings of the present inventive concept. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

It will be understood that when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present. Other words used to describe therelationship between elements should be interpreted in a like fashion(e.g., “between” versus “directly between,” “adjacent” versus “directlyadjacent,” etc.).

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting of thepresent inventive concept. As used herein, the singular forms “a,” “an”and “the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. It will be further understood thatthe terms “comprises” and/or “comprising,” when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this inventive concept belongs. Itwill be further understood that terms, such as those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

FIG. 1 illustrates a block diagram a video encoding apparatus 100according to some example embodiments. Referring to FIG. 1, the videoencoding apparatus 100 may include a motion estimation module 110, afiltering module 120, an information providing module 130, a motioncompensation module 140, a converting module 150, a bit streamgenerating module 160, a recovery module 170, and a storage unit 180.

The motion estimation module 110 performs a plurality of modes(inter-mode, intra-mode, etc.) of motion estimations on macro-blocksincluded in an input frame F(n) by referring to a reference frame F(r)provided from the storage unit 180 and provides a motion-estimated frameF(n)2, which conforms to a predetermined standard. The predeterminedstandard may be associated with each cost of the plurality of modes ofmotion estimations preformed on the macro-blocks. The cost of the motionestimation conforming to the predetermined standard may be lower thanthe costs of other modes of motion estimations. The cost of each mode ofmotion estimation may be determined based on a cost function.

The information providing module 130 receives motion vectors MV and modeinformation MODE of the plurality of modes of motion estimations toprovide an encoding information signal EIS. The encoding informationsignal EIS may include at least the motion vectors, the modeinformation, a partition type of the macro-blocks, a type (inter, intra,etc) of the macro-blocks, and a quantization parameter of themacro-blocks.

The filtering module 120 filters the motion-estimated frame F(n)2 fromthe motion estimation module 110 to provide a filtered frame M(n) basedon the encoding information signal EIS.

The motion compensation module 140 performs a motion compensation on thefiltered frame M(n) to provide a motion-compensated frame. Theconverting module 150 performs a spatial conversion on themotion-compensated frame. The bit stream generating module 160 generatesa bit stream BIT STREAM including the spatial-converted andmotion-compensated frame, the motion frames, and a number of thereference frame.

The recovery module 170 recovers the spatial-converted frame to providea recovered frame. The storage unit 180 stores the recovered frame andprovides the recovered frame as the reference frame F(r).

FIG. 2 illustrates a block diagram of an example of the motionestimation module 110 in FIG. 1 according to some example embodiments.Referring to FIG. 2, the motion estimation module 110 includes a motionestimation unit 111 and a mode decision unit 112.

The motion estimation unit 111 performs the plurality of modes of motionestimations on each of the macro-blocks of the input frame F(n) byreferring corresponding blocks of the reference frame to generatecorresponding motion vectors MV. The mode decision unit 112 decideswhich one of the plurality of modes of motion-estimated frames F(n)1conforms to the predetermined standard. That is, the mode decision unit112 decides which one of the plurality of modes of motion-estimatedframes F(n)1 costs less than other modes. For example, when inter-modemotion estimations are performed on each of the macro-blocks of theinput frame F(n), a motion vector is generated by searching for a regionthat is similar to the current macro-block to be encoded in at least onereference frame that precedes or follows the current input frame F(n) tobe encoded. For example, when intra-mode motion estimations areperformed on each of the macro-blocks of the input frame F(n), aprediction value of a current block to be encoded is computed usingpixel values of pixels located around the current macro-block, and adifference between the prediction value and an actual pixel value of thecurrent macro-block is encoded.

FIG. 3 illustrates an example of the filtering module 120 in FIG. 1according to some example embodiments. Referring to FIG. 3, thefiltering module 120 includes a two dimensional filter 121, amultiplexer 122, a switch 123, and a coupler 124.

The two dimensional filter 121 filters the motion-estimated frame F(n)2in two dimensions. The multiplexer 122 selects one of themotion-estimated frame F(n)2 and an output of the two dimensional filter121 in response to the encoding information signal EIS. The switch 123selectively provides the reference frame F(r) according to the encodinginformation signal EIS. The coupler 124 selectively couples the outputof the multiplexer 122 and the reference frame F(r) which is selectivelyprovided, to provide the filtered frame M(n) according to the encodinginformation signal EIS. For example, the multiplexer 122 selects theoutput of the two dimensional filter 121, the switch 123 is opened andthe coupler 124 provides the output of the two dimensional filter 121when the encoding information signal EIS indicates an intra-mode. Thatis, the motion compensation module 140 calculates a differenceprediction value using adjacent pixels of the macro-block to be encodedand actual pixel values. For example, the multiplexer 122 selects themotion-estimated frame F(n)2, the switch 123 is closed, and the coupler124 provides a frame in which the motion-estimated frame F(n)2 iscoupled with the reference frame F(r) as the filtered frame M(n) whenthe encoding information signal EIS indicates an inter-mode. The motioncompensation module 140 calculates a difference between a predictionblock using a motion vector generated in the motion estimation module110 and a current block. That is, the filtering module 120 combined withthe motion estimation module 110 operate as a third dimensional noisecanceller.

FIG. 4 illustrates a block diagram of an example of the convertingmodule 150 in FIG. 1 according to some example embodiments. Referring toFIG. 4, the converting module 150 includes a discrete cosinetransformation (DCT) unit 151 and a quantization unit 152.

The DCT unit 151 performs DCT on the motion-compensated frame togenerate DCT coefficients. The DCT coefficients may be real numbers. Thequantization unit 152 performs quantization on the DCT coefficients togenerate quantization coefficients. The quantization coefficients may beintegers. When a difference of an input frame and a prediction frame isgreat, the quantization coefficients may be made small, such that muchdata are encoded. When a difference of the input frame and theprediction frame is small, the quantization coefficients may be madegreat, such that less data are encoded.

The quantization coefficients are provided to the bit stream generatingmodule 160, and the bit stream generating module 160 generate the bitstream BIT STREAM including the spatial-converted frame, the motionvectors and a number of the reference frame. The converting module 150may include a wavelet converter instead of the DCT unit 151. The DCTunit 151 may cancel spatial overlap of the motion-compensated frame. Thequantization coefficients may be entropy-encoded by an entropy codingmodule (not illustrated) to be provided to the bit stream generatingmodule 160. The coded frame, the motion vectors, encoding informationand a required header are bit-streamed in the stream generating module160.

FIG. 5 illustrates a block diagram of an example of a recovery module170 in FIG. 1 according to some example embodiments. Referring to FIG.5, a recovery module 170 includes an inverse quantization unit 171 andan inverse discrete cosine transformation (IDCT) unit 172. The inversequantization unit 171 performs the inverse quantization on the spatialconverted frame. The IDCT unit 172 performs the IDCT on the inverselyquantized frame to provide a recovered frame. The recovered frame isprovided to the storage unit 180.

FIG. 6 illustrates a block diagram of a video encoding apparatus 200according to other example embodiments. Referring to FIG. 6, the videoencoding apparatus 200 includes a motion estimation module 210, afiltering module 220, an information providing module 230, a motioncompensation module 240, a converting module 250, a bit streamgenerating module 260, and a recovery module 270.

The architecture and operation of each of the motion estimation module210, the information providing module 230, the motion compensationmodule 240, the converting module 250, the bit stream generating module260, and the recovery module 270 are substantially the same asarchitecture and operation of the corresponding modules of the videoencoding apparatus 100 in FIG. 1. Therefore, detailed description of themotion estimation module 210, the information providing module 230, themotion compensation module 240, the converting module 250, the bitstream generating module 260, and the recovery module 270 will be not berepeated. The video encoding apparatus 200 in FIG. 6 differs from thevideo encoding apparatus 100 in FIG. 1 in that the filtering module 220differs from the filtering module 120.

FIG. 7 illustrates an example of the filtering module 220 in FIG. 6according to some example embodiments. Referring to FIG. 7, thefiltering module 220 includes a two dimensional filter 221, amultiplexer 222, a buffer 223, and a coupler 224.

The two dimensional filter 221 filters the motion-estimated frame F(n)2in two dimensions. The multiplexer 222 selects one of themotion-estimated frame F(n)2 and an output of the two dimensional filter221 in response to the encoding information signal EIS. The buffer 223stores the recovered frame, and selectively provides the recovered frameas the reference frame F(r) according to the encoding information signalEIS. The coupler 224 selectively couples the output of the multiplexer222 and the reference frame F(r) which is selectively provided, toprovide the filtered frame M(n) according to the encoding informationsignal EIS.

For example, the multiplexer 222 selects the output of the twodimensional filter 221, the buffer 223 does not provide the referenceframe F(r), and the coupler 224 provides the output of the twodimensional filter 121 as the filtered frame M(n) when the encodinginformation signal EIS indicates an intra-mode. That is, the motioncompensation module 240 calculates a difference prediction value usingadjacent pixels of the macro-block to be encoded and actual pixelvalues. For example, the multiplexer 222 selects the motion-estimatedframe F(n)2, the buffer 223 provides the reference frame F(r), and thecoupler 224 provides a frame in which the motion-estimated frame F(n)2is coupled with the reference frame F(r) as the filtered frame M(n) whenthe encoding information signal EIS indicates an inter-mode. The motioncompensation module 240 calculates a difference between a predictionblock using a motion vector generated in the motion estimation module210 and a current block. That is, the filtering module 220 combined withthe motion estimation module 210 operate as a third dimensional noisecanceller. The buffer 223 may be shared with other modules in the videoencoding apparatus 200.

FIGS. 8A and 8B illustrate simulation diagrams of peak signal to noiseratio (PSNR) of the video encoding apparatus according to some exampleembodiments. FIG. 8A illustrates PSNRs of the video encoding apparatusaccording to some example embodiments and a conventional video encodingapparatus when an sample image, e.g., a sunflower, including noise isencoded according to intra, predictive, and predictive (IPP) encodingscheme. FIG. 8B illustrates PSNRs of the video encoding apparatusaccording to example embodiments and the conventional video encodingapparatus when the sample image including noise is encoded according tointra, predictive, and bidirectional (IPB) encoding scheme.

In FIGS. 8A and 8B, reference numerals 311 and 321 indicate the PSNRs ofthe video encoding apparatus according to some example embodiments andreference numerals 313 and 323 indicate the PSNRs of the conventionalvideo encoding apparatus. Referring to FIGS. 8A and 8B, the PSNR of thesome example embodiments does not decrease when the bitrates increaseand the video encoding apparatus according to some example embodimentshas a relatively higher PSNR.

FIGS. 9A and 9B illustrate simulation diagrams of structural similarityindex measurement (SSIM) of the video encoding apparatus according tosome example embodiments. The SSIM may be criteria illustrating how muchan encoded image is similar to a real image. FIG. 9A illustrates SSIMsof the video encoding apparatus according to some example embodimentsand a conventional video encoding apparatus when a sample image, e.g., asunflower, including noise is encoded according to IPP encoding scheme.FIG. 9B illustrates SSIMs of the video encoding apparatus according toexample embodiments and the conventional video encoding apparatus whenthe sample image including noise is encoded according to IPB encodingscheme.

In FIGS. 9A and 9B, reference numerals 411 and 421 indicate the SSIMs ofthe video encoding apparatus according to some example embodiments andreference numerals 413 and 4323 indicate the SSIMs of the conventionalvideo encoding apparatus. Referring to FIGS. 9A and 9B, the SSIM of thesome example embodiments does not decrease when the bitrates increase,and the video encoding apparatus according to some example embodimentshas a relatively higher SSIM.

FIG. 10 illustrates a flow chart of a video encoding method according tosome example embodiments. Hereinafter, the video encoding method will bedescribed in detail with reference to FIGS. 1 and 10.

A plurality of modes of motion estimations are performed on macro-blocksincluded in a input frame F(n) by referring to a reference frame F(r) toprovide a motion-estimated frame F(n)2 which conforms to a predeterminedstandard in operation S310. Here, the predetermined standard may beassociated with each cost of the plurality of modes of motionestimations preformed on the macro-blocks. The motion-estimated frameF(n)2 is filtered to provide a filtered frame M(n) according to anencoding information signal EIS including motion vectors of theplurality of modes of motion estimations and a mode information of theplurality of modes of motion estimations in operation S320. The encodinginformation signal EIS may be provided from the information providingmodule 130 or may be provided externally. A motion compensation isperformed on the filtered frame M(n) in operation S330. The spatialconversion is performed on the motion-compensated frame in operationS340. The spatial conversion cancels spatial overlaps in themotion-compensated frame.

As mentioned above, some example embodiments may prevent bit rates fromincreasing and may prevent the image quality from being degraded withoutlosing bandwidth or increasing processing time by including a filterinside the video encoding apparatus and using additional encodinginformation.

The foregoing is illustrative of example embodiments and is not to beconstrued as limiting thereof. Although a few example embodiments havebeen described, those skilled in the art will readily appreciate thatmany modifications are possible in the example embodiments withoutmaterially departing from the novel teachings and advantages of thepresent inventive concept. Accordingly, all such modifications areintended to be included within the scope of the present inventiveconcept as defined in the claims. Therefore, it is to be understood thatthe foregoing is illustrative of various example embodiments and is notto be construed as limited to the specific example embodimentsdisclosed, and that modifications to the disclosed example embodiments,as well as other example embodiments, are intended to be included withinthe scope of the appended claims.

1. A video encoding apparatus, comprising: a motion estimation moduleconfigured to perform a plurality of modes of motion estimations onmacro-blocks included in an input frame and configured to provide amotion-estimated frame which conforms to a predetermined standard; aninformation providing module configured to receive motion vectors andmode information of the plurality of modes of motion estimations toprovide an encoding information signal; a filtering module configured tofilter the motion-estimated frame to provide a filtered frame based onthe encoding information signal; a motion compensation module configuredto perform a motion compensation on the filtered frame to provide amotion-compensated frame; and a converting module configured to performa spatial conversion on the motion-compensated frame.
 2. The videoencoding apparatus as claimed in claim 1, wherein the predeterminedstandard is associated with each cost of the plurality of modes ofmotion estimations performed on the macro-blocks.
 3. The video encodingapparatus as claimed in claim 2, wherein a cost of the mode of motionestimation conforming to the predetermined standard is lower than a costof other modes of motion estimations.
 4. The video encoding apparatus asclaimed in claim 1, wherein the plurality of modes of motion estimationsare performed by referring to a reference frame.
 5. The video encodingapparatus as claimed in claim 4, wherein the motion estimation moduleincludes: a motion estimation unit configured to perform the pluralityof modes of motion estimations on each of the macro-blocks by referringcorresponding blocks of the reference frame to generate correspondingmotion vectors; and a mode decision unit configured to decide which oneof the modes conforms to the predetermined standard.
 6. The videoencoding apparatus as claimed in claim 5, wherein the encodinginformation signal includes at least the motion vectors, the modeinformation, a partition type of the macro-blocks, a type of themacro-blocks, and a quantization parameter of the macro-blocks.
 7. Thevideo encoding apparatus as claimed in claim 4, wherein the filteringmodule includes: a two dimensional filter that filters themotion-estimated frame in two dimensions; a multiplexer that selects oneof the motion-estimated frame and an output of the two dimensionalfilter in response to the encoding information signal; a switch thatselectively provides the reference frame according to the encodinginformation signal; and a coupler that selectively couples the output ofthe multiplexer and the reference frame which is selectively provided toprovide the filtered frame according to the encoding information signal.8. The video encoding apparatus as claimed in claim 7, wherein, when theencoding information signal indicates an intra-mode, the multiplexerselects the output of the two dimensional filter, the switch is opened,and the coupler provides output of the two dimensional filter.
 9. Thevideo encoding apparatus as claimed in claim 7, wherein, when theencoding information signal indicates an inter-mode, the multiplexerselects the motion-estimated frame, the switch is closed, and thecoupler provides a frame in which the motion-estimated frame is coupledwith the reference frame as the filtered frame.
 10. The video encodingapparatus as claimed in claim 7, wherein the motion estimation moduleand the filtering module operates as a third-dimensional noise cancellerwhen the motion estimation module and the filtering module are coupledto each other.
 11. The video encoding apparatus as claimed in claim 4,wherein the filtering module includes: a two dimensional filter thatfilters the motion-estimated frame in two dimensions; a multiplexer thatselects one of the motion-estimated frame and an output of the twodimensional filter in response to the encoding information signal; abuffer that stores the reference frame to selectively provide the storedreference frame according to the encoding information signal; and acoupler that selectively couples the output of the multiplexer and thereference frame which is selectively provided to provide the filteredframe according to the encoding information signal.
 12. The videoencoding apparatus as claimed in claim 4, wherein the converting moduleincludes: a discrete cosine transformation (DCT) unit that performs DCTon the motion-estimated frame to generate a DCT coefficient; and aquantization unit that performs quantization on the DCT coefficient togenerate a quantization coefficient.
 13. The video encoding apparatus asclaimed in claim 4, further comprising: a recovery module configured torecover the spatial-converted frame to provide a recovered frame; and astorage unit that stores the recovered frame to provide the storedrecovered frame as the reference frame.
 14. The video encoding apparatusas claimed in claim 13, wherein the recovery module includes: an inversequantization unit that performs the inverse quantization on the spatialconverted frame; and an inverse discrete cosine transformation thatperforms the inverse discrete cosine transformation on the inverselyquantized frame to provide the recovered frame.
 15. A video encodingmethod, comprising: performing a plurality of modes of motionestimations on macro-blocks included in a input frame by referring to areference frame to provide a motion-estimated frame which conforms to apredetermined standard; filtering the motion-estimated frame to providea filtered frame according to an encoding information signal includingmotion vectors of the plurality of modes of motion estimations and amode information of the plurality of modes of motion estimations;performing a motion compensation on the filtered frame; and performing aspatial conversion on the motion-compensated frame.
 16. The videoencoding method as claimed in claim 15, wherein the predeterminedstandard is associated with each cost of the plurality of modes ofmotion estimations preformed on the macro-blocks.
 17. The video encodingmethod as claimed in claim 15, performing the spatial conversionincludes cancelling spatial overlaps in the motion-compensated frame.